One of the many remarkable features of St Mary Magdalene's history is its relationship with the Orthodox Church. Successive bishops of Adelaide have gladly made Anglican churches available to the Orthodox for worship.

As early as the 1920s, the fledgling Greek Orthodox community used the church for worship, including the first visit to South Australia of Archbishop Christophoros Knitis, first Metropolitan of the Greek Orthodox Church in Australia, in 1924. The second Metropolitan, Archbishop Timotheus Evangelinidis, first visited in in 1932.

The Syrian Orthodox worshipped at St Mary Magdalene's, both jointly with the Greek Orthodox, and with their own priests when one was available. The Right Rev. Archimandrite Antonius Mobayed, Who came to Australia in 1931 to lead the first Syrian Orthodox community in Melbourne, visited Adelaide to celebrate the liturgy soon after his arrival.

In the early 1950s, the Serbian Orthodox participated in the English liturgies at St Mary Magdalene's, and celebrated their own liturgies when a priest was present. On 27 January 1952, St. Sava's Day was celebrated by Fr Georgia (George) Djonlich, one of five Serbian priests who came to Australia among the many Serbs displaced in the years after World War II. Fr Djonlich had been a chaplain in the Yugoslav army when he was captured during the German invasion of Yugoslavia in 1941, spending four years in a POW camp. He came to Australia in 1950, and was called by the local Serbian community to come to Adelaide in 1951. The liturgy was celebrated in the presence of the Church of England Bishop of Adelaide, Bishop Robin, who was later presented with an Orthodox-style bishop's mitre. The Serbian community moved to their own church, itself a former Congregational church, in Hindmarsh in 1953.

The Russian Orthodox also used the church prior to the erection of their own church in 1950 (replaced in 1963 with the beautiful Novgorod-style St Nicholas' Church at Wayville).

In 2017, the Coptic Orthodox community of St Mary and Anba Bishoy celebrated the Divine Liturgy on the Feast Day of St Mary Magdalene.

Thanks be to God for all that the churches hold in common, and for ongoing dialogue, as we share in the prayer of Christ: ‘May they all be one.’